1. Field of the Invention
The present invention relates to an improved window sash construction. More particularly, the present invention relates to a homogeneous window sash construction, and a method and apparatus for the manufacture thereof. Most particularly, the present invention relates to a homogeneous window sash construction which holds a pair of glazing in a spaced apart parallel relationship without the necessity for spacers, and a method and apparatus for making the same utilizing a double door horizontal booking press.
2. Discussion of the related art
The present invention is directed to a two step reaction injection molding (RIM) process for fabricating an encapsulated double glazed (DG) sash unit without a prefabricated spacer. Previously the manufacturer of an encapsulated DG unit required two distinct processes. First, the glazing, such as glass sheets, were assembled and, second, they were sealed in a typical insulated glazing operation. The prefabricated insulating glass assembly was then placed in a suitable mold, and an encapsulating frame was formed around the periphery of the assembly.
U.S. Pat. No. 4,219,517 discloses a composite glass and molded frame member. One or more glass panels may be utilized in association with a generally U-shaped elastomeric packing, and a mold-seal strip with thin leg portions engaging the glass. A perimeter frame of urethane plastic material is molded over the pre-assembled glass edge and seal assembly.
U.S. Pat. Nos. 4,822,649 and 4,909,875 show a multiple glazing, a method of obtaining the same, and a device for carrying out the method. The glazing contains two sheets of glass separated by a space of dehydrated air and maintained by a cross-braced frame, of which at least the surface in contact with the glass is butyl and/or polyisobutylene rubber-base mastic and is covered with a peripheral injection which adheres in a cohesive manner to the mastic of the cross-braced frame.
U.S. Pat. No. 4,951,927 discloses an encapsulated multiple glaze structure formed by positioning at least two spaced apart substantially co-extensive sheets of glazing material, wherein the sheets are maintained in an aligned spaced relationship by a suitable spacer element adjacent the peripheral portions of the facing surfaces of the glazing sheets. The above assemblage is then typically placed within the mold cavity of a suitable molding apparatus and a charge of an elastomeric gasket forming material is injected therein to form an encapsulating gasket around the peripheral edge portions of the assemblage to produce a multiple glazed structure.
U.S. Pat. No. 5,061,531 discloses an insulating architectural glass unit for various applications having at least two panes of glass plates separated by an encapsulated air space. The device is constructed with an injection molded frame of relatively low thermal conductivity material. The glass unit has a pair of glass plate sections held apart by aluminum, plastic, or fiber glass separator strips.
All of the above patents show an insulating glass assembly being fabricated in one operation followed by an encapsulation in a second discreet operation.
Two U.K. patents, GB2 245,300 B and GB2 245,861 B disclose the encapsulation of insulating assemblies using modular molds. The molds are comprised of at least one discreet mold structure for each edge of the glass assembly to be encapsulated. In some embodiments disclosed in the ""861 patent, and all the embodiments disclosed in the ""300 patent, the discreet mold structures are comprised of ridged frame members which are secured to the glass assembly during the encapsulation process to form the finished architectural glazing unit.
The U.K. ""861 patent discloses a modular mold process for encapsulating a variety of sizes of insulating glass assemblies. This is accomplished using four independent corner sections and four side sections of length suitable for the assembly being encapsulated.
U.S. Pat. No. 4,470,534 discloses an adjustable frame to accommodate different size glass sheet assemblies in the manufacture of insulating glazing panels. However, no encapsulation is involved.
The PCT Publication WO 99/14169 teaches the manufacture of a multi-panel insulating glazing unit without a prefabricated insulating glass assembly. No encapsulation process is involved in the manufacture.
The above-mentioned patents show various double glazed window assemblies and methods to make the same. The apparatus to make the devices shown often involve large and complicated molding process. This often necessitates the devices being made at a separate plant and shipped for installation. Since all of the above-patents either show an insulating glass assembly being fabricated in one operation, followed by encapsulation in a second discreet operation, or teach the manufacture of an insulating glazing unit without an encapsulation process being involved in the manufacture, those skilled in the art continued to search for a better way of fabricating an encapsulated double glazed sash unit without a prefabricated spacer.
The aforementioned problems in the art are addressed in accordance with the present invention by the provision of a novel sash structure not hereto found in the prior art, together with a novel method and apparatus for its manufacture. In one of its broad aspects, the present invention is a homogeneous sash which may be made of a wide variety of materials, and holds a first and a second pane of glazing material in a parallel spaced apart relationship without the use of spacers, or a preassembled glazing unit. The use of more than two spaced apart glazing in the sash construction of the present invention is well within the scope of the present invention.
In one embodiment of the present invention, a pair of glass sheets which comprise the insulated glazing assembly are sealed in a spaced apart parallel relationship during the formation of the window sash in a two-step encapsulation project.
In another embodiment of the invention, a mold assembly for forming the sash construction is comprised of three individual sections or mold parts. The first section supports the first glass sheet and cooperates with the second section to define a cavity to produce a first, formed, portion of the window sash. After an initial injection step which encapsulates the peripheral edge of the first glazing to the form the first portion of the unit, the second mold section is removed. A third mold section with a second glazing sheet supported therein is then placed into intimate contact with the first mold section, and the just formed portion of the sash construction. The mold cavity created therebetween defines the second portion of the sash construction. The second glass sheet is positioned in a spaced relationship to the first glazing, and is in sealing contact along its peripheral edge with the first formed portion. The second injection step encapsulates the edge and free side of the second glazing sheet while bonding with the previously formed first portion to complete the sash and the encapsulation process.
In a further embodiment of the invention, an adjustable mold for fabricating a variety of sashes is disclosed. An adjustable fixed mold is provided which may replace the fixed mold in other embodiments of the invention. The adjustable fixed mold has an adjustable mold base with a right angle portion having a first adjustable mold portion and a second adjustable mold portion, and having a portion of a fan gate, sprue, and recess formed therein. A first complementary adjustable mold portion and a second complementary adjustable mold portion, each having a portion of a fan gate, sprue, and recess may be used with the adjustable mold base.
In yet another embodiment of the invention, a method is disclosed of making the improved window sash construction whereby a fixed mold is provided into which a first sheet of glazing is inserted. When a first complimentary mold portion is placed in an intimate 180xc2x0 opposed or mating contact with the fixed mold portion, a mold cavity is formed about the entire periphery of the glass sheet. When a reaction injection molding material is introduced into the mold cavity so formed, a first formed portion of the window sash construction is formed, encapsulating the first sheet.
The first complimentary mold portion is then removed, and a second complimentary mold portion is placed in a 180xc2x0 opposed relationship in intimate or mating contact with the fixed mold. The shape of the mold cavity so formed is such that when a reaction injection molding material is introduced into the second mold cavity, the second sheet or pane of glazing will be encapsulated, and a second formed portion of the homogeneous sash will be formed. The second complimentary mold portion is then removed and the window sash construction of the present invention holding a pair of glazing sheets in a spaced apart parallel relationship without the need for spacers or a preformed insulating glazing assembly is produced.
In a still further embodiment of the present invention, a molding apparatus is described which may practice the aforementioned method.
Thus, one of the objects of the present invention is to provide a novel window sash construction.
Another object of the present invention is to provide a molding apparatus which is compact and easily moveable from place to place for forming the improved window sash construction of the present invention.
Another object of the present invention is to provide a method for forming the improved window sash construction of the present invention.
Further objects and advantages of the present invention will be apparent from the following description and appended claims, reference being made to the accompanying drawings forming a part of the specification, wherein like reference characters designate corresponding parts in the several views.